//
//  ScrollingStackViewController.swift
//  Stacks
//
//  Created by Keith Harrison http://useyourloaf.com
//  Copyright (c) 2016 Keith Harrison. All rights reserved.
//
//  Redistribution and use in source and binary forms, with or without
//  modification, are permitted provided that the following conditions are met:
//
//  1. Redistributions of source code must retain the above copyright
//  notice, this list of conditions and the following disclaimer.
//
//  2. Redistributions in binary form must reproduce the above copyright
//  notice, this list of conditions and the following disclaimer in the
//  documentation and/or other materials provided with the distribution.
//
//  3. Neither the name of the copyright holder nor the names of its
//  contributors may be used to endorse or promote products derived from
//  this software without specific prior written permission.
//
//  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
//  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
//  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
//  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
//  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
//  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
//  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
//  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
//  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
//  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
//  POSSIBILITY OF SUCH DAMAGE.

import UIKit

final class ScrollingStackViewController: UIViewController {
    @IBOutlet private var scrollView: UIScrollView!
    @IBOutlet private var stackView: UIStackView!

    @IBAction func singleTap(_ sender: UITapGestureRecognizer) {
        let heartImage = UIImage(named: "Heart")
        let heartImageView = UIImageView(image: heartImage)
        stackView.addArrangedSubview(heartImageView)
        scrollToEnd(heartImageView)
    }

    @IBAction func twoFingerTap(_ sender: UITapGestureRecognizer) {
        let starImage = UIImage(named: "Star")
        let starImageView = UIImageView(image: starImage)
        stackView.addArrangedSubview(starImageView)
        scrollToEnd(starImageView)
    }

    @IBAction func threeFingerTap(_ sender: UITapGestureRecognizer) {
        let views = stackView.arrangedSubviews
        for entry in views {
            stackView.removeArrangedSubview(entry)
            entry.removeFromSuperview()
        }
    }

    private func scrollToEnd(_ addedView: UIView) {
        let contentViewHeight = scrollView.contentSize.height + addedView.bounds.height + stackView.spacing
        let offsetY = contentViewHeight - scrollView.bounds.height
        if offsetY > 0 {
            scrollView.setContentOffset(CGPoint(x: scrollView.contentOffset.x, y: offsetY), animated: true)
        }
    }
}
